fix(stream):fix the race condition when creating new tsables.

source/dnode/vnode/src/tq/tqExec.c

@@ -68,14 +68,14 @@ int32_t tqScanData(STQ* pTq, const STqHandle* pHandle, SMqDataRsp* pRsp, STqOffs
   int32_t vgId = TD_VID(pTq->pVnode);
 
   if (qStreamPrepareScan(task, pOffset, pHandle->execHandle.subType) < 0) {
-    tqDebug("prepare scan failed, return, consumer:0x%"PRIx64, pHandle->consumerId);
+    tqDebug("prepare scan failed, vgId:%d, consumer:0x%"PRIx64, vgId, pHandle->consumerId);
     if (pOffset->type == TMQ_OFFSET__LOG) {
       pRsp->rspOffset = *pOffset;
       return 0;
     } else {
       tqOffsetResetToLog(pOffset, pHandle->snapshotVer);
       if (qStreamPrepareScan(task, pOffset, pHandle->execHandle.subType) < 0) {
-        tqDebug("prepare scan failed, return, consumer:0x%"PRIx64, pHandle->consumerId);
+        tqDebug("prepare scan failed, vgId:%d, consumer:0x%"PRIx64, vgId, pHandle->consumerId);
         pRsp->rspOffset = *pOffset;
         return 0;
       }

source/libs/executor/inc/executil.h

@@ -107,6 +107,7 @@ int32_t         tableListGetGroupList(const STableListInfo* pTableList, int32_t
 uint64_t        tableListGetSize(const STableListInfo* pTableList);
 uint64_t        tableListGetSuid(const STableListInfo* pTableList);
 STableKeyInfo*  tableListGetInfo(const STableListInfo* pTableList, int32_t index);
+int32_t         tableListFind(const STableListInfo* pTableList, uint64_t uid, int32_t startIndex);
 
 size_t getResultRowSize(struct SqlFunctionCtx* pCtx, int32_t numOfOutput);
 void   initResultRowInfo(SResultRowInfo* pResultRowInfo);

source/libs/executor/inc/executorimpl.h

@@ -143,10 +143,7 @@ typedef struct {
   SQueryTableDataCond tableCond;
   int64_t             fillHistoryVer1;
   int64_t             fillHistoryVer2;
-
-  // int8_t        triggerSaved;
-  // int64_t       deleteMarkSaved;
-  SStreamState* pState;
+  SStreamState*       pState;
 } SStreamTaskInfo;
 
 typedef struct {
@@ -168,15 +165,14 @@ typedef struct STaskStopInfo {
 } STaskStopInfo;
 
 struct SExecTaskInfo {
-  STaskIdInfo   id;
-  uint32_t      status;
-  STimeWindow   window;
-  STaskCostInfo cost;
-  int64_t       owner;  // if it is in execution
-  int32_t       code;
-  int32_t       qbufQuota;  // total available buffer (in KB) during execution query
-
-  int64_t               version;  // used for stream to record wal version, why not move to sschemainfo
+  STaskIdInfo           id;
+  uint32_t              status;
+  STimeWindow           window;
+  STaskCostInfo         cost;
+  int64_t               owner;      // if it is in execution
+  int32_t               code;
+  int32_t               qbufQuota;  // total available buffer (in KB) during execution query
+  int64_t               version;    // used for stream to record wal version, why not move to sschemainfo
   SStreamTaskInfo       streamInfo;
   SSchemaInfo           schemaInfo;
   STableListInfo*       pTableInfoList;  // this is a table list
@@ -188,6 +184,7 @@ struct SExecTaskInfo {
   SLocalFetch           localFetch;
   SArray*               pResultBlockList;  // result block list
   STaskStopInfo         stopInfo;
+  SRWLatch              lock;              // secure the access of STableListInfo
 };
 
 enum {

source/libs/executor/src/executil.c

@@ -34,7 +34,7 @@ struct STableListInfo {
   int32_t   numOfOuputGroups;  // the data block will be generated one by one
   int32_t*  groupOffset;       // keep the offset value for each group in the tableList
   SArray*   pTableList;
-  SHashObj* map;  // speedup acquire the tableQueryInfo by table uid
+  SHashObj* map;               // speedup acquire the tableQueryInfo by table uid
   uint64_t  suid;
 };
 
@@ -1800,6 +1800,21 @@ STableKeyInfo* tableListGetInfo(const STableListInfo* pTableList, int32_t index)
   return taosArrayGet(pTableList->pTableList, index);
 }
 
+int32_t tableListFind(const STableListInfo* pTableList, uint64_t uid, int32_t startIndex) {
+  int32_t numOfTables = taosArrayGetSize(pTableList->pTableList);
+  if (startIndex >= numOfTables) {
+    return -1;
+  }
+
+  for (int32_t i = startIndex; i < numOfTables; ++i) {
+    STableKeyInfo* p = taosArrayGet(pTableList->pTableList, i);
+    if (p->uid == uid) {
+      return i;
+    }
+  }
+  return -1;
+}
+
 uint64_t getTableGroupId(const STableListInfo* pTableList, uint64_t tableUid) {
   int32_t* slot = taosHashGet(pTableList->map, &tableUid, sizeof(tableUid));
   ASSERT(pTableList->map != NULL && slot != NULL);

source/libs/executor/src/executor.c

@@ -410,6 +410,7 @@ int32_t qUpdateQualifiedTableId(qTaskInfo_t tinfo, const SArray* tableIdList, bo
     }
 
     STableListInfo* pTableListInfo = pTaskInfo->pTableInfoList;
+    taosWLockLatch(&pTaskInfo->lock);
 
     for (int32_t i = 0; i < numOfQualifiedTables; ++i) {
       uint64_t*     uid = taosArrayGet(qa, i);
@@ -424,6 +425,7 @@ int32_t qUpdateQualifiedTableId(qTaskInfo_t tinfo, const SArray* tableIdList, bo
           if (code != TSDB_CODE_SUCCESS) {
             taosMemoryFree(keyBuf);
             taosArrayDestroy(qa);
+            taosWUnLockLatch(&pTaskInfo->lock);
             return code;
           }
         }
@@ -445,6 +447,7 @@ int32_t qUpdateQualifiedTableId(qTaskInfo_t tinfo, const SArray* tableIdList, bo
       tableListAddTableInfo(pTableListInfo, keyInfo.uid, keyInfo.groupId);
     }
 
+    taosWUnLockLatch(&pTaskInfo->lock);
     if (keyBuf != NULL) {
       taosMemoryFree(keyBuf);
     }
@@ -452,7 +455,9 @@ int32_t qUpdateQualifiedTableId(qTaskInfo_t tinfo, const SArray* tableIdList, bo
     taosArrayDestroy(qa);
   } else {  // remove the table id in current list
     qDebug(" %d remove child tables from the stream scanner", (int32_t)taosArrayGetSize(tableIdList));
+    taosWLockLatch(&pTaskInfo->lock);
     code = tqReaderRemoveTbUidList(pScanInfo->tqReader, tableIdList);
+    taosWUnLockLatch(&pTaskInfo->lock);
   }
 
   return code;
@@ -1000,6 +1005,7 @@ int32_t qStreamRestoreParam(qTaskInfo_t tinfo) {
   }
   return 0;
 }
+
 bool qStreamRecoverScanFinished(qTaskInfo_t tinfo) {
   SExecTaskInfo* pTaskInfo = (SExecTaskInfo*)tinfo;
   return pTaskInfo->streamInfo.recoverScanFinished;
@@ -1080,8 +1086,11 @@ int32_t qStreamSetScanMemData(qTaskInfo_t tinfo, SPackedData submit) {
 }
 
 int32_t qStreamPrepareScan(qTaskInfo_t tinfo, STqOffsetVal* pOffset, int8_t subType) {
-  SExecTaskInfo* pTaskInfo = (SExecTaskInfo*)tinfo;
-  SOperatorInfo* pOperator = pTaskInfo->pRoot;
+  SExecTaskInfo*  pTaskInfo = (SExecTaskInfo*)tinfo;
+  SOperatorInfo*  pOperator = pTaskInfo->pRoot;
+  STableListInfo* pTableListInfo = pTaskInfo->pTableInfoList;
+  const char*     id = GET_TASKID(pTaskInfo);
+
   pTaskInfo->streamInfo.prepareStatus = *pOffset;
   pTaskInfo->streamInfo.returned = 0;
 
@@ -1095,20 +1104,23 @@ int32_t qStreamPrepareScan(qTaskInfo_t tinfo, STqOffsetVal* pOffset, int8_t subT
     // TODO add more check
     if (pOperator->operatorType != QUERY_NODE_PHYSICAL_PLAN_STREAM_SCAN) {
       if(pOperator->numOfDownstream != 1){
-        qError("pOperator->numOfDownstream != 1:%d", pOperator->numOfDownstream);
+        qError("invalid operator, number of downstream:%d, %s", pOperator->numOfDownstream, id);
         return -1;
       }
       pOperator = pOperator->pDownstream[0];
     }
 
     SStreamScanInfo* pInfo = pOperator->info;
+    STableScanInfo*  pScanInfo = pInfo->pTableScanOp->info;
+    STableScanBase*  pScanBaseInfo = &pScanInfo->base;
+
     if (pOffset->type == TMQ_OFFSET__LOG) {
-      STableScanInfo* pTSInfo = pInfo->pTableScanOp->info;
-      tsdbReaderClose(pTSInfo->base.dataReader);
-      pTSInfo->base.dataReader = NULL;
+      tsdbReaderClose(pScanBaseInfo->dataReader);
+      pScanBaseInfo->dataReader = NULL;
+
       // let's seek to the next version in wal file
       if (tqSeekVer(pInfo->tqReader, pOffset->version + 1, pTaskInfo->id.str) < 0) {
-        qError("tqSeekVer failed ver:%" PRId64, pOffset->version + 1);
+        qError("tqSeekVer failed ver:%, %s" PRId64, pOffset->version + 1, id);
         return -1;
       }
     } else if (pOffset->type == TMQ_OFFSET__SNAPSHOT_DATA) {
@@ -1117,120 +1129,120 @@ int32_t qStreamPrepareScan(qTaskInfo_t tinfo, STqOffsetVal* pOffset, int8_t subT
       int64_t uid = pOffset->uid;
       int64_t ts = pOffset->ts;
 
+      // this value may be changed if new tables are created
+      taosRLockLatch(&pTaskInfo->lock);
+      int32_t numOfTables = tableListGetSize(pTableListInfo);
+
       if (uid == 0) {
-        if (tableListGetSize(pTaskInfo->pTableInfoList) != 0) {
-          STableKeyInfo* pTableInfo = tableListGetInfo(pTaskInfo->pTableInfoList, 0);
+        if (numOfTables != 0) {
+          STableKeyInfo* pTableInfo = tableListGetInfo(pTableListInfo, 0);
           uid = pTableInfo->uid;
           ts = INT64_MIN;
         } else {
-          qError("uid == 0 and tablelist size is 0");
+          taosRUnLockLatch(&pTaskInfo->lock);
+          qError("no table in table list, %s", id);
           return -1;
         }
       }
 
-      /*if (pTaskInfo->streamInfo.lastStatus.type != TMQ_OFFSET__SNAPSHOT_DATA ||*/
-      /*pTaskInfo->streamInfo.lastStatus.uid != uid || pTaskInfo->streamInfo.lastStatus.ts != ts) {*/
-      STableScanInfo* pTableScanInfo = pInfo->pTableScanOp->info;
-      int32_t         numOfTables = tableListGetSize(pTaskInfo->pTableInfoList);
-
-      qDebug("switch to table uid:%" PRId64 " ts:%" PRId64 "% "PRId64 " rows returned", uid, ts, pInfo->pTableScanOp->resultInfo.totalRows);
       pInfo->pTableScanOp->resultInfo.totalRows = 0;
 
-      bool found = false;
-      for (int32_t i = 0; i < numOfTables; i++) {
-        STableKeyInfo* pTableInfo = tableListGetInfo(pTaskInfo->pTableInfoList, i);
-        if (pTableInfo->uid == uid) {
-          found = true;
-          pTableScanInfo->currentTable = i;
-          break;
-        }
-      }
+      // start from current accessed position
+      int32_t index = tableListFind(pTableListInfo, uid, pScanInfo->currentTable);
+      taosRUnLockLatch(&pTaskInfo->lock);
 
-      // TODO after dropping table, table may not found
-      if(!found){
-        qError("uid not found in tablelist %" PRId64, uid);
+      if (index >= 0) {
+        pScanInfo->currentTable = index;
+      } else {
+        qError("uid:%" PRIu64 " not found in table list, total:%d %s", uid, numOfTables, id);
         return -1;
       }
 
-      if (pTableScanInfo->base.dataReader == NULL) {
-        STableKeyInfo* pList = tableListGetInfo(pTaskInfo->pTableInfoList, 0);
-        int32_t        num = tableListGetSize(pTaskInfo->pTableInfoList);
-
-        if (tsdbReaderOpen(pTableScanInfo->base.readHandle.vnode, &pTableScanInfo->base.cond, pList, num,
-                           pTableScanInfo->pResBlock, &pTableScanInfo->base.dataReader, NULL) < 0 ||
-            pTableScanInfo->base.dataReader == NULL) {
-          qError("tsdbReaderOpen failed. uid:%" PRIi64, pOffset->uid);
+      STableKeyInfo keyInfo = {.uid = uid};
+      if (pScanBaseInfo->dataReader == NULL) {
+        int32_t code = tsdbReaderOpen(pScanBaseInfo->readHandle.vnode, &pScanBaseInfo->cond, &keyInfo, 1,
+                                      pScanInfo->pResBlock, &pScanBaseInfo->dataReader, NULL);
+        if (code != TSDB_CODE_SUCCESS) {
+          qError("prepare read tsdb snapshot failed, uid:%" PRId64 ", code:%s %s", pOffset->uid, tstrerror(code), id);
+          terrno = code;
           return -1;
         }
-      }
+      } else {
+        tsdbSetTableList(pScanBaseInfo->dataReader, &keyInfo, 1);
+        int64_t oldSkey = pScanBaseInfo->cond.twindows.skey;
+
+        // let's start from the next ts that returned to consumer.
+        pScanBaseInfo->cond.twindows.skey = ts + 1;
+        tsdbReaderReset(pScanBaseInfo->dataReader, &pScanBaseInfo->cond);
 
-      STableKeyInfo tki = {.uid = uid};
-      tsdbSetTableList(pTableScanInfo->base.dataReader, &tki, 1);
-      int64_t oldSkey = pTableScanInfo->base.cond.twindows.skey;
-      pTableScanInfo->base.cond.twindows.skey = ts + 1;
-      tsdbReaderReset(pTableScanInfo->base.dataReader, &pTableScanInfo->base.cond);
-      pTableScanInfo->base.cond.twindows.skey = oldSkey;
-      pTableScanInfo->scanTimes = 0;
+        // restore the key value
+        pScanBaseInfo->cond.twindows.skey = oldSkey;
+        pScanInfo->scanTimes = 0;
 
-      qDebug("tsdb reader offset seek snapshot to uid:%" PRId64 " ts %" PRId64 ", table cur set to %d , all table num %d", uid,
-             ts, pTableScanInfo->currentTable, numOfTables);
+        qDebug("tsdb reader offset seek snapshot to uid:%" PRId64 " ts %" PRId64 "  table index:%d numOfTable:%d, %s",
+               uid, ts, pScanInfo->currentTable, numOfTables, id);
+      }
     } else {
-      qError("invalid pOffset->type:%d", pOffset->type);
-      return -1;
-    }
-  } else if (pOffset->type == TMQ_OFFSET__SNAPSHOT_DATA) {
-    SStreamRawScanInfo* pInfo = pOperator->info;
-    SSnapContext*       sContext = pInfo->sContext;
-    if (setForSnapShot(sContext, pOffset->uid) != 0) {
-      qError("setDataForSnapShot error. uid:%" PRIi64, pOffset->uid);
+      qError("invalid pOffset->type:%d, %s", pOffset->type, id);
       return -1;
     }
 
-    SMetaTableInfo mtInfo = getUidfromSnapShot(sContext);
-    tsdbReaderClose(pInfo->dataReader);
-    pInfo->dataReader = NULL;
+  } else {  // subType == TOPIC_SUB_TYPE__TABLE/DB
+    if (pOffset->type == TMQ_OFFSET__SNAPSHOT_DATA) {
+      SStreamRawScanInfo* pInfo = pOperator->info;
+      SSnapContext*       sContext = pInfo->sContext;
+      if (setForSnapShot(sContext, pOffset->uid) != 0) {
+        qError("setDataForSnapShot error. uid:%" PRIi64, pOffset->uid);
+        return -1;
+      }
 
-    cleanupQueryTableDataCond(&pTaskInfo->streamInfo.tableCond);
-    tableListClear(pTaskInfo->pTableInfoList);
+      SMetaTableInfo mtInfo = getUidfromSnapShot(sContext);
+      tsdbReaderClose(pInfo->dataReader);
+      pInfo->dataReader = NULL;
 
-    if (mtInfo.uid == 0) {
-      return 0;  // no data
-    }
+      cleanupQueryTableDataCond(&pTaskInfo->streamInfo.tableCond);
+      tableListClear(pTableListInfo);
 
-    initQueryTableDataCondForTmq(&pTaskInfo->streamInfo.tableCond, sContext, &mtInfo);
-    pTaskInfo->streamInfo.tableCond.twindows.skey = pOffset->ts;
+      if (mtInfo.uid == 0) {
+        return 0;  // no data
+      }
 
-    if (pTaskInfo->pTableInfoList == NULL) {
-      pTaskInfo->pTableInfoList = tableListCreate();
-    }
+      initQueryTableDataCondForTmq(&pTaskInfo->streamInfo.tableCond, sContext, &mtInfo);
+      pTaskInfo->streamInfo.tableCond.twindows.skey = pOffset->ts;
 
-    tableListAddTableInfo(pTaskInfo->pTableInfoList, mtInfo.uid, 0);
+//      if (pTableListInfo == NULL) {
+//        pTableListInfo = tableListCreate();
+//      }
 
-    STableKeyInfo* pList = tableListGetInfo(pTaskInfo->pTableInfoList, 0);
-    int32_t        size = tableListGetSize(pTaskInfo->pTableInfoList);
+      tableListAddTableInfo(pTableListInfo, mtInfo.uid, 0);
 
-    tsdbReaderOpen(pInfo->vnode, &pTaskInfo->streamInfo.tableCond, pList, size, NULL, &pInfo->dataReader, NULL);
+      STableKeyInfo* pList = tableListGetInfo(pTableListInfo, 0);
+      int32_t        size = tableListGetSize(pTableListInfo);
 
-    cleanupQueryTableDataCond(&pTaskInfo->streamInfo.tableCond);
-    strcpy(pTaskInfo->streamInfo.tbName, mtInfo.tbName);
-    tDeleteSSchemaWrapper(pTaskInfo->streamInfo.schema);
-    pTaskInfo->streamInfo.schema = mtInfo.schema;
+      tsdbReaderOpen(pInfo->vnode, &pTaskInfo->streamInfo.tableCond, pList, size, NULL, &pInfo->dataReader, NULL);
 
-    qDebug("tmqsnap qStreamPrepareScan snapshot data uid:%" PRId64 " ts %" PRId64, mtInfo.uid, pOffset->ts);
-  } else if (pOffset->type == TMQ_OFFSET__SNAPSHOT_META) {
-    SStreamRawScanInfo* pInfo = pOperator->info;
-    SSnapContext*       sContext = pInfo->sContext;
-    if (setForSnapShot(sContext, pOffset->uid) != 0) {
-      qError("setForSnapShot error. uid:%" PRIu64 " ,version:%" PRId64, pOffset->uid, pOffset->version);
-      return -1;
+      cleanupQueryTableDataCond(&pTaskInfo->streamInfo.tableCond);
+      strcpy(pTaskInfo->streamInfo.tbName, mtInfo.tbName);
+      tDeleteSSchemaWrapper(pTaskInfo->streamInfo.schema);
+      pTaskInfo->streamInfo.schema = mtInfo.schema;
+
+      qDebug("tmqsnap qStreamPrepareScan snapshot data uid:%" PRId64 " ts %" PRId64, mtInfo.uid, pOffset->ts);
+    } else if (pOffset->type == TMQ_OFFSET__SNAPSHOT_META) {
+      SStreamRawScanInfo* pInfo = pOperator->info;
+      SSnapContext*       sContext = pInfo->sContext;
+      if (setForSnapShot(sContext, pOffset->uid) != 0) {
+        qError("setForSnapShot error. uid:%" PRIu64 " ,version:%" PRId64, pOffset->uid, pOffset->version);
+        return -1;
+      }
+      qDebug("tmqsnap qStreamPrepareScan snapshot meta uid:%" PRId64 " ts %" PRId64, pOffset->uid, pOffset->ts);
+    } else if (pOffset->type == TMQ_OFFSET__LOG) {
+      SStreamRawScanInfo* pInfo = pOperator->info;
+      tsdbReaderClose(pInfo->dataReader);
+      pInfo->dataReader = NULL;
+      qDebug("tmqsnap qStreamPrepareScan snapshot log");
     }
-    qDebug("tmqsnap qStreamPrepareScan snapshot meta uid:%" PRId64 " ts %" PRId64, pOffset->uid, pOffset->ts);
-  } else if (pOffset->type == TMQ_OFFSET__LOG) {
-    SStreamRawScanInfo* pInfo = pOperator->info;
-    tsdbReaderClose(pInfo->dataReader);
-    pInfo->dataReader = NULL;
-    qDebug("tmqsnap qStreamPrepareScan snapshot log");
   }
+
   return 0;
 }
 

source/libs/executor/src/executorimpl.c

@@ -1989,6 +1989,7 @@ static SExecTaskInfo* doCreateExecTaskInfo(uint64_t queryId, uint64_t taskId, in
   pTaskInfo->stopInfo.pStopInfo = taosArrayInit(4, sizeof(SExchangeOpStopInfo));
   pTaskInfo->pResultBlockList = taosArrayInit(128, POINTER_BYTES);
 
+  taosInitRWLatch(&pTaskInfo->lock);
   pTaskInfo->id.vgId = vgId;
   pTaskInfo->id.queryId = queryId;
   pTaskInfo->id.str = buildTaskId(taskId, queryId);

source/libs/executor/src/scanoperator.c

@@ -766,8 +766,8 @@ static SSDataBlock* doTableScan(SOperatorInfo* pOperator) {
 
       STableKeyInfo* pTableInfo = tableListGetInfo(pTaskInfo->pTableInfoList, pInfo->currentTable);
       tsdbSetTableList(pInfo->base.dataReader, pTableInfo, 1);
-      qDebug("set uid:%" PRIu64 " into scanner, total tables:%d, index:%d %s", pTableInfo->uid, numOfTables,
-             pInfo->currentTable, pTaskInfo->id.str);
+      qDebug("set uid:%" PRIu64 " into scanner, total tables:%d, index:%d/%d %s", pTableInfo->uid, numOfTables,
+             pInfo->currentTable, numOfTables, pTaskInfo->id.str);
 
       tsdbReaderReset(pInfo->base.dataReader, &pInfo->base.cond);
       pInfo->scanTimes = 0;
@@ -1569,19 +1569,16 @@ static int32_t setBlockIntoRes(SStreamScanInfo* pInfo, const SSDataBlock* pBlock
 static SSDataBlock* doQueueScan(SOperatorInfo* pOperator) {
   SExecTaskInfo*   pTaskInfo = pOperator->pTaskInfo;
   SStreamScanInfo* pInfo = pOperator->info;
+  const char* id = GET_TASKID(pTaskInfo);
 
-  qDebug("start to exec queue scan");
+  qDebug("start to exec queue scan, %s", id);
 
   if (pTaskInfo->streamInfo.submit.msgStr != NULL) {
-    if (pInfo->tqReader->msg2.msgStr == NULL) {
-      /*pInfo->tqReader->pMsg = pTaskInfo->streamInfo.pReq;*/
 
-      /*const SSubmitReq* pSubmit = pInfo->tqReader->pMsg;*/
-      /*if (tqReaderSetDataMsg(pInfo->tqReader, pSubmit, 0) < 0) {*/
-      /*void* msgStr = pTaskInfo->streamInfo.*/
+    if (pInfo->tqReader->msg2.msgStr == NULL) {
       SPackedData submit = pTaskInfo->streamInfo.submit;
       if (tqReaderSetSubmitReq2(pInfo->tqReader, submit.msgStr, submit.msgLen, submit.ver) < 0) {
-        qError("submit msg messed up when initing stream submit block %p", submit.msgStr);
+        qError("submit msg messed up when initing stream submit block %p, %s", submit.msgStr, id);
         pInfo->tqReader->msg2 = (SPackedData){0};
         pInfo->tqReader->setMsg = 0;
         ASSERT(0);
@@ -1615,18 +1612,20 @@ static SSDataBlock* doQueueScan(SOperatorInfo* pOperator) {
   if (pTaskInfo->streamInfo.prepareStatus.type == TMQ_OFFSET__SNAPSHOT_DATA) {
     SSDataBlock* pResult = doTableScan(pInfo->pTableScanOp);
     if (pResult && pResult->info.rows > 0) {
-      qDebug("queue scan tsdb return %d rows min:%" PRId64 " max:%" PRId64 " wal curVersion:%" PRId64, pResult->info.rows,
-             pResult->info.window.skey, pResult->info.window.ekey, pInfo->tqReader->pWalReader->curVersion);
+      qDebug("queue scan tsdb return %d rows min:%" PRId64 " max:%" PRId64 " wal curVersion:%" PRId64" %s", pResult->info.rows,
+             pResult->info.window.skey, pResult->info.window.ekey, pInfo->tqReader->pWalReader->curVersion, id);
       pTaskInfo->streamInfo.returned = 1;
       return pResult;
     } else {
+      // no data has return already, try to extract data in the WAL
       if (!pTaskInfo->streamInfo.returned) {
         STableScanInfo* pTSInfo = pInfo->pTableScanOp->info;
         tsdbReaderClose(pTSInfo->base.dataReader);
-        qDebug("3");
+
         pTSInfo->base.dataReader = NULL;
         tqOffsetResetToLog(&pTaskInfo->streamInfo.prepareStatus, pTaskInfo->streamInfo.snapshotVer);
-        qDebug("queue scan tsdb over, switch to wal ver %" PRId64 "", pTaskInfo->streamInfo.snapshotVer + 1);
+
+        qDebug("queue scan tsdb over, switch to wal ver:%" PRId64 " %s", pTaskInfo->streamInfo.snapshotVer + 1, id);
         if (tqSeekVer(pInfo->tqReader, pTaskInfo->streamInfo.snapshotVer + 1, pTaskInfo->id.str) < 0) {
           tqOffsetResetToLog(&pTaskInfo->streamInfo.lastStatus, pTaskInfo->streamInfo.snapshotVer);
           return NULL;
@@ -1643,7 +1642,7 @@ static SSDataBlock* doQueueScan(SOperatorInfo* pOperator) {
       if (tqNextBlock(pInfo->tqReader, &ret) < 0) {
         // if the end is reached, terrno is 0
         if (terrno != 0) {
-          qError("failed to get next log block since %s", terrstr());
+          qError("failed to get next log block since %s, %s", terrstr(), id);
         }
       }
 
@@ -1658,9 +1657,6 @@ static SSDataBlock* doQueueScan(SOperatorInfo* pOperator) {
       } else if (ret.fetchType == FETCH_TYPE__META) {
         qError("unexpected ret.fetchType:%d", ret.fetchType);
         continue;
-        //        pTaskInfo->streamInfo.lastStatus = ret.offset;
-        //        pTaskInfo->streamInfo.metaBlk = ret.meta;
-        //        return NULL;
       } else if (ret.fetchType == FETCH_TYPE__NONE ||
                  (ret.fetchType == FETCH_TYPE__SEP && pOperator->status == OP_EXEC_RECV)) {
         pTaskInfo->streamInfo.lastStatus = ret.offset;
@@ -1672,7 +1668,7 @@ static SSDataBlock* doQueueScan(SOperatorInfo* pOperator) {
       }
     }
   } else {
-    qError("unexpected streamInfo prepare type: %d", pTaskInfo->streamInfo.prepareStatus.type);
+    qError("unexpected streamInfo prepare type: %d %s", pTaskInfo->streamInfo.prepareStatus.type, id);
     return NULL;
   }
 }